Sunday, November 13, 2016

Physical Review: XFX RX 480 GTR

Thank you to XFX for giving me the GPU.

The backplate adds rigidity and is separate from the main heasink so it's not necessary to remove both if you want to get to the front of the PCB. It does not help cool the PCB but the holes over the VRM section stop it from causing unnecessary heat build up in the VRM area.

Cooling

The noise measurements were taken 20cm away from the card on an open air test bench.
The GPU was kept under load by the Graphics Test 1 from 3Dmark Firestrike running windowed using the regular preset windowed at1440x900p with 8xMSAA.
The OC test is 1420Mhz core with +50% power limit +100mv using sapphire Trixx.
I test from the lowest fan speed to the highest this means that I actually wait for temperatures to come down this prevents me from getting low temperature measurements by taking measurements too early.Notes:
Both the Kryonaut and stock thermal paste ended up hitting the thermal throttle of the card which is 90°C which is why they both ended up with identical Delta T in the graph.

An important thing to note is that due to the way the GTR's heatsink dumps hot air you will want to put some aiflow in front of the card's fans or they will end up re-using air that already went through the heatsink which leads to sub optimal thermal performance. If you have good case airflow this should be none issue. If you're not sure I recomend that you try playing with fan placemenets a little. If you don't want to mess with airflow you'll have to live with the noise of higher fan speed because as far as I know all the custom 480s have the same problem and the reference card is really really loud if you want get some real OCing done.

I think the heatsink is quiet up to about 55% fan speed then again I have a pretty high tolerance for noise since I like to use 2000RPM fans for pretty much everything.

For the Vcore VRM XFX opted to go with the the IRF6811 and IRF6894. These are the same FETs you would see in the VRM of a Fury X. The GTR also has 6 phases. Which is the same as a Fury X. The end result is that with the default switching frequency of the 304KHz the XFX RX 480 GTR has the most powerful VRM of any RX 480. With 366A available even at 125°C the GTR is capable of handling pretty much any overclocking you might want to do on it and it will do it without even needing a heatsink on the VRM as long as you give it some airflow.

The VRAM and AUX VRMs are or on par with what you would see on most other RX 480s.The APW8722A has a fixed switching frequency of 600KHz(+/-10%) so both the AUX and VRAM should get rather clean power. Both offer plenty of power as the RX 480's memory system runs on about 35W at stock.

Extras:

Dual BIOS
0RPM fans in idle
VRAM cooling plate
Hard swap fans

Conlusion

I love the RX 480 GTR. It offers a very strong Vcore VRM perfect for any type of overclocking you decided to go for. It's also one of the few RX 480s with a BIOS switch. Which I think is a must have for anyone into BIOS modding(I am). The heatsink may not be the most powerful one I've ever seen however it is perfectly capable for both 24/7 usage and benchmarking runs. My only concern with the card is that the Vcore VRM pulls half it's power from the 12V pins of the PCI-e slot. At stock clocks this is not an issue however when you really push an RX 480 the power draw goes through the roof and that could lead to a burn out 24 pin connector if you are running several RX 480 GTRs. But that's really only an issue for me since I'm toying with idea of doing a 4 way RX 480 benching session.

If you like the content you see on AHOC please donate to my Patreon so that I can make more/better content.